FIELD OF THE INVENTION
The invention relates to a cleaning device for a printing press, having a cloth spindle formed with a slot or a longitudinal groove, a cleaning cloth clampable in the slot, and a clamping body rotatable inside the slot.
Cleaning devices of the foregoing general type are used for cleaning printing ink and other contaminants from rollers, cylinders and drums.
In the published European Patent Document EP 07 95 402 A1, a cylinder cleaning device of this type is described having a cloth spindle formed with a variable circumference. In accordance with one embodiment thereof, a bar that firmly clamps the cleaning cloth to the bottom of a trench formed in the cloth spindle can have an oval cross section and can be embodied so as to be rotatable from a clamping position into a released position in order to undo the clamping. Rotating the bar out of the released position and into the clamping position for the purpose of firmly clamping the cleaning cloth is neither contemplated nor, for structural reasons, possible in this arrangement. On the contrary, this heretofore known arrangement requires that the cleaning cloth be wound in multiple layers around the bar, that is located partly in the trench and partly protruding therefrom, in order to achieve firm clamping. The cloth spindle is unsuited for use as a clean cloth spindle because, when the end of the cloth is reached, the required cloth tension is lost, and the bar falls out of the trench. If the cloth spindle is used as a dirty cloth spindle, all of the cleaning cloth cannot be optimally used, because a relatively long section thereof always remains unused for producing the clamping needed for cleaning purposes. Furthermore, it is not possible to wind the cloth uniformly onto the bar, because the bar protruding from the trench very severely deforms the winding layers at some locations thereof.
A washing device is also described in German Utility Model DE 297 06 836 U1, but it does not match the general type of washing or cleaning device described at the introduction hereto, and the spindle of this prior art device has a slot or longitudinal groove wherein an end of a washcloth is clamped in place by a clamping or lug strip. The clamping strip is not constructed so as to be rotatable inside the longitudinal groove. Although this heretofore known washing device does permit a more exact fastening of the washcloth to the spindle than if adhesive tapes are used, nevertheless the clamping is insecure. Depending upon the nature of the washcloth that is clamped in place, either the washcloth can slip out of the clamped condition, or the resilient clamping strip can snap or spring out of the clamping position. This risk is especially great when a relatively major tensile force is applied to the washcloth. Such a tensile force acts upon the washcloth after the end of the winding is reached when the cloth has been unwound. The washcloth torn out of the clamped condition thereof can be pulled into the printing press and cause severe damage.